step(ci,(ci,s),tm(s,[pri(naught,[]),pri(naught,[])],pri(lst,[pri(h,[ctxm(beta_1_,u,bsn,i_bsn,i_bsn)]),pri(h,[pri(lst,[pri(h,[ctxm(beta_1_,u,bsn,i_bsn,i_bsn)]),ctxm(beta_1_,r,dom, (dom,r,beta_1_), (dom,r,beta_1_))])]),ctxm(beta_1_,r,dom, (dom,r,beta_1_), (dom,r,beta_1_)),ctxm(beta_1_,u,d_1, (i,d_1), (c,d_1)),ctxm(beta_1_,u,d_4, (i,d_4), (c,d_4))]))).